The short answer: most first-time visitors to Marrakech should stay inside the medina. The experience of stepping out of a riad directly into a thousand-year-old street — brass lanterns, the smell of tanned leather, the sound of a hammered copper workshop two doors down — is the kind of thing you remember long after the trip. A modern hotel in Gueliz is comfortable and practical, but it is not why most people come to Marrakech.
That said, the medina is not for everyone. The alleys are genuinely bewildering for the first 48 hours, taxis cannot get near most riads, and some central streets are noisy until late. If you are travelling with a toddler in a pushchair, need step-free access, or simply want to sleep without earplugs, the new town has real advantages.
Below is an honest breakdown of every factor — neighbourhood by neighbourhood, with indicative prices — so you can decide which version of Marrakech suits your trip.